The present invention relates to a respiratory monitor, and in particular to an electromechanical transducer device for monitoring respiratory movements of a person, primarily for monitoring cot-death syndrome of infants.
The present invention also relates to a device and method for imparting a stimulus to a sleeping being, and in particular, to a device and method wherein the occurance of a predetermined condition may be detected, and upon detection, thereof, operate a stimulation means to consciously or subconsciously provide a stimulus to said being.
A number of devices are presently known for monitoring respiratory movements of persons, and in particular for monitoring cot-death syndrome of infants. Much of the development of such devices has been limited by the technology at hand, and in particular the technology as far as electrical transducer devices are concerned.
For instance, AU-B-29443/87 in the name of J. K. Frost relates to an electromechanical transducer for detecting movements of the human body. The invention discloses a device which comprises a compressible pad constructed of `cellophane` material or the like, the device also having a microphone, such that during compression/expansion a noise is produced by the `cellophane`, and a signal is generated therefrom. GB-A-1469488 in the name of F. A. Chandler et al discloses a granular flow sensing and switching device, wherein, the device is utilised to detect flow by means of placing a probe with a microphone in the flow and detecting an acoustic signal. The signal is then processed to give an indication as to the flow of, for instance, grains striking the probe. An electrical capacitance device is disclosed in AU-A-73917/81, wherein a plurality or sensor members are arranged one on the other such that the variation of spacing between adjacent sheets may be measured by a measure of the variation of electrical capacitance therebetween. AU-B-58956/80 in the name of E. B. Cohen discloses a movement monitoring device comprising a tubular housing with end caps and containing a freely movable ball bearing and, according to movement of the ball, an electrical signal is supplied representative of the physical activity of a person. U.S. Pat. No. 3,875,929 in the name J. T. Grant utilises a microwave radar means which provides a movement sensitive field of microwave radiation. U.S. Pat. No. 3,926,177 in the name of E. V. Hardway also utilises a resilient capacitive pad adapted to respond to the movement of a body by providing a capacitive change.
It is therefore seen that, whilst the devices for monitoring respiratory movement are common, their advance is generally the improvement in the transducer means associated therewith, or, to an improvement in the arrangement of the particular transducer device.
In more recent times, for instance as disclosed in U.S. Pat. No. 4,359,726 in the name of J. Lewiner et al, piezo-electric transducers are utilised. The device disclosed in the abovementioned U.S. Pat. No. 4,359,726 comprises a foil interposed between two films. The foil is sensitive to pressure variations applied locally to it. AU-A-46089/85 in the name of R. Benkendorf et al also discloses the use of a piezo-electric transducer device. The construction of the Benkendorf et al device is quite complex, specifically, being a rigid base with a flexible top, between which are provided a pad. The flexible top has two rigid members, the ends being provided with a piezo-electric transducer therebetween. Upon the imposition of a force on the flexible top, which results in relative angular movement between each of the rigid members, this movement is sensed by the transducer which supplies an appropriate signal to an suitable processing circuit.
It will therefore be understood that much development has been undertaken in respect of movement detection devices, primarily associated with the advances in technology. However, despite the more recent advances, that is, the advances in respect of piezo-electric transducer devices, an efficient and sensitive device has still not yet been constructed. It will be appreciated that, particularly when the respiratory monitor is adapted to monitor cot-death syndrome, the provision of an extremely sensitive fail-safe device is imperative. Failure of a transducer to respond could well result in death of a child, and, should such a device have a low reliability by excess false triggering, an alarm signal may be prone to be ignored by an operator.
Also, various devices are known to provide some form of stimulation to persons. For example, reference is made to U.S. Pat. No. 5,002,144 by the Applicant. In this aforementioned Patent specification, there is provided a device for imparting an orbital motion to a wheeled baby carriage or cot. This device is particularly designed to provide a rocking motion, which perhaps stimulates a prenatal motion within a mother's womb. This rocking device is particularly advantageous for rocking an infant to sleep.
The present invention seeks to overcome the disadvantages of the prior art, by providing a highly sensitive and accurate monitoring device for the detection of respiratory movements of a person.
The present invention seeks to provide a device which combines these unique and different technologies in providing a device which detects the occurance of a predetermined condition such as respiratory disfunction, and upon detection of such predetermined condition, either consciously or subconsciously provide a stimulus. It will be appreciated that the provision of the stimulus then "reminds" the person or other being of the occurance of the predetermined condition such that the being then automatically either consciously or subconsciously reacts to effectively discontinue the pre-determined condition.